The pupil expander of my issued U.S. Pat. No. 5,267,553 comprises a ring of silicone or other suitable soft plastic tubular material (e.g. Silastic.RTM.silicone, Dow Corning, durometer value of about 80) with an outside diameter of 8.2 millimeters and an inside diameter of 7.0 millimeters. The ring has a C-shaped cross-sectional configuration with a peripheral opening at the outside edge. The ring is incomplete with approximately a 3.5 millimeter gap to permit surgical maneuvers within it, and that gap is bridged by a strap between the open ends of the ring. There are also two tabs with holes, which are used for manipulation of the device inside and outside the eye.
In operation, when it is desired to insert the pupil expander into the eye during a surgical procedure, the expander is first mounted on a carrier block or delivery case, as described in my co-pending patent application with said description being incorporated by reference herein. The pupil expander is then stretched into an elongated condition wherein the pupil expander is in a convenient position for removal and handling. My previous patent applications describe the use of forceps to manipulate the pupil expander.
The method of use of this pupil expander comprises the moving of the pupil expander, which is inserted into the anterior chamber of the eye through a previously prepared scleral or corneal incision. The expander is advanced across the anterior chamber until the flared end of the expander engages the iris at a 6 o'clock position. A spatula or lens manipulator is used to hold the expander in place against the iris sphincter while the forceps tips are partially withdrawn. The tips are then closed on the expander, and the tips are advanced into the eye causing the expander to enlarge horizontally engaging additional iris. The tips are then withdrawn an additional millimeter or two, and the above maneuver is repeated until the expander has been advanced onto the sphincter and the pupil has been gradually dilated. When the forceps have been withdrawn until they are opposite the tabs on the expander, the handle is lifted pushing the tips and the contained expander down toward the lens permitting the tabs to come down against the iris and completing the placement of the expander entirely within the pupil.
Because of the extremely small size of the pupil expander, the handling thereof is very delicate and sensitive, and ordinary forceps are not adapted for easily handling thereof.
It is therefore a principal object of the invention to provide apparatus for easily grasping and manipulating the pupil expander of my co-pending application to insert the expander in an eye without the need for a second instrument.
These and other objects will be apparent to those skilled in the art.